Kimi Watanabe-Finster is a fictional character on the animated television series Rugrats and spin-off All Grown Up!. She first appeared in Rugrats in Paris in 1998. She is the stepsister of Chuckie Finster; born into a Japanese family, she was the last character to be introduced to the Rugrats character list when her mother, Kira, married Chaz Finster, the father of Chuckie Finster, a regular character on the show and a tomboy. She later appeared in the series All Grown Up!.She appeared in the last two Rugrats films.

Kimi was the last addition to the cast of Rugrats, making her first appearance in the second Rugrats movie, Rugrats in Paris: The Movie. She is depicted as being chubby with purple hair, tied up in three pigtails on top of her head. She wears a pink shirt, yellow dress with a purple cat on it, wearing a diaper underneath (Like Lil) and purple cowgirl boots.

She was introduced as Chuckie's new stepsister, after her mother, Kira Watanabe-Finster, married Chuckie's father, Chas Finster, after she divorced Hiro Watanabe, Kimi's father.

Kimi was the last addition to the cast of Rugrats, making her first appearance in the second Rugrats movie, Rugrats in Paris. In Rugrats, the one and a half year old Kimi was portrayed as very brave and often stumbled into dangerous situations she was too naïve to recognize, often bringing her new stepbrother, Chuckie Finster, along, much to his dismay. He described her as "another Tommy" upon meeting her. Chuckie and Kimi bond almost instantly as Kimi looks at him as "the best big brother ever".

She is depicted as being slightly chubby with dark hair, tied up in three pigtails on top of her head. She wears a pink shirt, yellow dress with a purple cat on it, wearing a diaper underneath (like Lil) and purple cowgirl boots.

She was introduced as Chuckie's new stepsister, after her mother, Kira Watanabe-Finster, married Chuckie's father, Chas Finster, Oddly enough though, in Finsterella, both Kira and Chas announced that they had each adopted Chuckie (Kira adopted him as his official mother) and Kimi (By Chas as her official father), they are still referred as stepchildren by a lot of people even though they never were referred to in that way during the series. This marriage and the changes it brought to the Finster family were used in Rugrats to teach the child viewers, by demonstration, about adapting to such drastic changes caused by death in a family and remarriage.

In All Grown Up!, set approximately nine years later, Kimi grew up to some extent. Kimi is still adventurous and free spirited and has also grown to be spunky, independent and more aware of other's feelings. She's very athletic; for example, at a ski resort, while Angelica signed up for spa-like activities, Kimi signed up for "daring" activities like rock climbing.

She had a tendency to buck the trend on how she feels about and treats less popular kids, including Z, and never judges people for their appearances. She was also portrayed as being supportive of her best friend Susie when she was in need. When Susie is having problems, Kimi is usually there to help. However, she is also portrayed as having a tendency to hold grudges. Angelica Pickles could be considered somewhat of an associate, but grudgingly so on Kimi's behalf.

Kimi has purple hair with is tied into 3 ponytails.She wears a yellow dress with a purple cat on it in the movie, although throughout the series she has a pink shirt inside.She has purple cowgirl boots and has a diaper underneath like Lil.